Acceleration sensor with double pairs of movable elements that compensate for substrate changes

ABSTRACT

A physical quantity sensor includes a substrate, a pair of first elements detecting acceleration in a first direction, and a pair of second elements detecting an acceleration in a second direction. The first element portion includes a first movable portion displaceable in the first direction, first and second movable electrode fingers disposed in the first movable portion, first and second fixing electrode fingers disposed to face the first and second movable electrode fingers, and first and second support portions supporting the first and second fixing electrode fingers. The second element includes a second movable portion displaceable in the second direction, third and fourth movable electrode fingers disposed in the second movable portion, third and fourth fixing electrode fingers disposed to face the third and fourth movable electrode fingers, and third and fourth support portions supporting the third and fourth fixing electrode fingers.

BACKGROUND 1. Technical Field

According to an aspect of the present disclosure relates to a physicalquantity sensor, a physical quantity sensor device, an electronicapparatus, a portable electronic apparatus, and a vehicle.

2. Related Art

For example, an acceleration sensor described in JP-T-2000-512023 is abiaxial acceleration sensor that can detect an acceleration in theX-axis direction and an acceleration in the Y-axis direction. Theacceleration sensor includes a substrate, a movable portion that isdisplaceable in the X-axis direction and the Y-axis direction withrespect to the substrate, a first X-axis movable electrode fingerextending from the movable portion toward a plus side in the Y-axisdirection, a second X-axis movable electrode finger extending from themovable portion toward a minus side in the Y-axis direction, a firstY-axis movable electrode finger extending from the movable portiontoward the plus side in the X-axis direction, a second Y-axis movableelectrode finger extending from the movable portion toward the minusside in the X-axis direction, a first X-axis fixing electrode fingerfacing the first X-axis movable electrode finger, a second X-axis fixingelectrode finger facing the second X-axis movable electrode finger, afirst Y-axis fixing electrode finger facing the first Y-axis movableelectrode finger, a second Y-axis fixing electrode finger facing thesecond Y-axis movable electrode finger, a first X support portion thatis bonded to the substrate and supports the first X-axis fixingelectrode finger, a second X support portion that is bonded to thesubstrate and supports the second X-axis fixing electrode finger, afirst Y support portion that is bonded to the substrate and supports thefirst Y-axis fixing electrode finger, and a second X support portionthat is bonded to the substrate and supports the second Y-axis fixingelectrode finger.

The acceleration sensor can detect an acceleration in the X-axisdirection, based on a change in electrostatic capacitance between thefirst X-axis movable electrode finger and the first X-axis fixingelectrode finger and a change in electrostatic capacitance between thesecond X-axis movable electrode finger and the second X-axis fixingelectrode finger, and can detect an acceleration in the Y-axisdirection, based on a change in electrostatic capacitance between thefirst Y-axis movable electrode finger and the first Y-axis fixingelectrode finger and a change in electrostatic capacitance between thesecond Y-axis movable electrode finger and the second Y-axis fixingelectrode finger.

However, in the acceleration sensor described in JP-T-2000-512023, thefirst X support portion and the second X support portion are located ona side opposite to the movable portion, and thereby, a separationdistance therebetween is increased. Accordingly, influence of warpage(heat deflection) on the substrate is different by the first X supportportion and the second X support portion, and a deviation occurs in theelectrostatic capacitance between the first X-axis movable electrodefinger and the first X-axis fixing electrode finger and in theelectrostatic capacitance between the second X-axis movable electrodefinger and the second X-axis fixing electrode finger due to temperature,and detection accuracy of the X-axis acceleration is reduced. This isthe same for the Y-axis acceleration. In this way, the accelerationsensor described in JP-T-2000-512023 is susceptible to the influence ofwarpage on the substrate, and cannot exert favorable temperaturecharacteristics.

SUMMARY

An advantage of some aspects of the invention is to provide a physicalquantity sensor, a physical quantity sensor device, an electronicapparatus, a portable electronic apparatus, and a vehicle capable ofexerting favorable temperature characteristics.

The invention can be implemented as the following configurations.

A physical quantity sensor according to an aspect of the inventionincludes a substrate, a pair of first elements that are disposed on thesubstrate and detect an acceleration in a first direction, and a pair ofsecond elements that are disposed on the substrate and detect anacceleration in a second direction orthogonal to the first direction, inwhich each of the pair of first elements includes a first movableportion that is displaceable in the first direction with respect to thesubstrate, a first movable electrode finger and a second movableelectrode finger that are disposed in the first movable portion, a firstfixing electrode finger that is disposed on one side in the firstdirection with respect to the first movable electrode finger, a firstsupport portion that is fixed to the substrate and supports the firstfixing electrode finger, a second fixing electrode finger that isdisposed on the other side in the first direction with respect to thesecond movable electrode finger, and a second support portion that isfixed to the substrate, is juxtaposed with the first support portion,and supports the second fixing electrode finger, and in which each ofthe pair of second elements includes a second movable portion that isdisplaceable in the second direction with respect to the substrate, athird movable electrode finger and a fourth movable electrode fingerthat are disposed in the second movable portion, a third fixingelectrode finger that is disposed on one side in the second directionwith respect to the third movable electrode finger, a third supportportion that is fixed to the substrate and supports the third fixingelectrode finger, a fourth fixing electrode finger that is disposed onthe other side in the second direction with respect to the fourthmovable electrode finger, and a fourth support portion that is fixed tothe substrate, is juxtaposed with the third support portion, andsupports the fourth fixing electrode finger.

With this configuration, it is possible to obtain a physical quantitysensor capable of reducing influence of heat deflection on a substrateand exerting favorable temperature characteristics.

In the physical quantity sensor according to the aspect of theinvention, it is preferable that each of the pair of first elementsincludes a first fixing portion that is fixed to the substrate and afirst spring that connects the first fixing portion to the first movableportion, the first movable portion is cantilever-supported to the firstfixing portion via the first spring, each of the pair of second elementsincludes a second fixing portion that is fixed to the substrate and asecond spring that connects the second fixing portion to the secondmovable portion, and the second movable portion is cantilever-supportedto the second fixing portion via the second spring.

With this configuration, for example, it is possible to reduce a size ofa physical quantity sensor, compared to a configuration in which a firstmovable portion and a second movable portion are supported at both ends.

In the physical quantity sensor according to the aspect of theinvention, it is preferable that, if an angular velocity that isobtained by using a third direction orthogonal to the first directionand the second direction as an axis is applied, a separation distancebetween the first movable electrode finger and the first fixingelectrode finger and a separation distance between the second movableelectrode finger and the second fixing electrode finger are separatedfrom or approach each other, in the pair of first elements, and aseparation distance between the third movable electrode finger and thethird fixing electrode finger and a separation distance between thefourth movable electrode finger and the fourth fixing electrode fingerare separated from or approach each other, in the pair of secondelements.

With this configuration, it is possible to reduce influence of anangular velocity.

In the physical quantity sensor according to the aspect of theinvention, it is preferable that when a first virtual line in the firstdirection and a second virtual line orthogonal to the first virtual linein the second direction are set and when among four quadrants that arepartitioned by the first virtual line and the second virtual line in aplan view, one set of quadrants facing an intersection point between thefirst virtual line and the second virtual line is referred to as a firstquadrant and a second quadrant and the other set is referred to as athird quadrant and a fourth quadrant, one of the pair of first elementsis disposed in the first quadrant and the other is disposed in thesecond quadrant, and one of the pair of second elements is disposed inthe third quadrant and the other is disposed in the fourth quadrant.

With this configuration, it is possible to dispose a first elementportion and a second element portion in a comparatively small space andto reduce a size of a physical quantity sensor.

In the physical quantity sensor according to the aspect of theinvention, it is preferable that the pair of first elements are disposedpoint-symmetrically with respect to the intersection point, and the pairof second elements are disposed point-symmetrically with respect to theintersection point.

With this configuration, it is possible to dispose four elements offirst and second elements in a well-balanced manner.

A physical quantity sensor device according to another aspect of theinvention includes the physical quantity sensor according to the aspectof the invention and a circuit element.

With this configuration, it is possible to obtain effects of a physicalquantity sensor according to the invention and to obtain a highlyreliable physical quantity sensor device.

An electronic apparatus according to another aspect of the inventionincludes the physical quantity sensor according to the aspect of theinvention, a control circuit, and a correction circuit.

With this configuration, it is possible to obtain effects of a physicalquantity sensor according to the invention and to obtain a highlyreliable electronic apparatus.

A portable electronic apparatus according to another aspect of theinvention includes the physical quantity sensor according to the aspectof the invention, a case that stores the physical quantity sensor, aprocessing unit that is stored in the case and processes output datafrom the physical quantity sensor, a display unit that is stored in thecase, and a light-transmitting cover that covers an opening of the case.

With this configuration, it is possible to obtain effects of a physicalquantity sensor according to the invention and to obtain a highlyreliable portable electronic apparatus.

A vehicle according to another aspect of the invention includes thephysical quantity sensor according to the aspect of the invention and aposture control circuit.

With this configuration, it is possible to obtain effects of a physicalquantity sensor according to the invention and to obtain a highlyreliable vehicle.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described with reference to the accompanyingdrawings, wherein like numbers reference like elements.

FIG. 1 is a plan view illustrating a physical quantity sensor accordingto a first embodiment.

FIG. 2 is a cross-sectional view taken along line A-A in FIG. 1.

FIG. 3 is a plan view illustrating an arrangement of four elements.

FIG. 4 is a perspective view illustrating the four elements.

FIG. 5 is a diagram illustrating voltages applied to the physicalquantity sensor illustrated in FIG. 1.

FIG. 6 is a cross-sectional view illustrating a state in which heatdeflection occurs in a substrate.

FIG. 7 is a plan view illustrating a state in which an angular velocityacts on the physical quantity sensor.

FIG. 8 is a plan view illustrating a modification example of thephysical quantity sensor illustrated in FIG. 1.

FIG. 9 is a plan view illustrating a physical quantity sensor accordingto a second embodiment.

FIG. 10 is a plan view illustrating a physical quantity sensor accordingto a third embodiment.

FIG. 11 is a plan view illustrating a physical quantity sensor accordingto a fourth embodiment.

FIG. 12 is a cross-sectional view illustrating a physical quantitysensor device according to a fifth embodiment.

FIG. 13 is a perspective view illustrating an electronic apparatusaccording to a sixth embodiment.

FIG. 14 is a perspective view illustrating an electronic apparatusaccording to a seventh embodiment.

FIG. 15 is a perspective view illustrating an electronic apparatusaccording to an eighth embodiment.

FIG. 16 is a plan view illustrating a portable electronic apparatusaccording to a ninth embodiment.

FIG. 17 is a functional block diagram illustrating a schematicconfiguration of the portable electronic apparatus illustrated in FIG.16.

FIG. 18 is a perspective view illustrating a vehicle according to atenth embodiment.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

Hereinafter, a physical quantity sensor, a physical quantity sensordevice, an electronic apparatus, a portable electronic apparatus, and avehicle according to the invention will be described in detail based onembodiments illustrated in the accompanying drawings.

First Embodiment

A physical quantity sensor according to a first embodiment will bedescribed.

FIG. 1 is a plan view illustrating a physical quantity sensor accordingto a first embodiment. FIG. 2 is a cross-sectional view taken along lineA-A in FIG. 1. FIG. 3 is a plan view illustrating an arrangement of fourelements. FIG. 4 is a perspective view illustrating the four elements.FIG. 5 is a diagram illustrating voltages applied to the physicalquantity sensor illustrated in FIG. 1. FIG. 6 is a cross-sectional viewillustrating a state in which heat deflection occurs in a substrate.FIG. 7 is a plan view illustrating a state in which an angular velocityacts on the physical quantity sensor. FIG. 8 is a plan view illustratinga modification example of the physical quantity sensor illustrated inFIG. 1. Hereinafter, for the sake of convenient description, a frontside of a paper surface of FIG. 1 and an upper side of FIG. 2 are alsoreferred to as “upper”, and a rear side of the paper surface of FIG. 1and a lower side of FIG. 2 are also referred to as “lower”. In addition,as illustrated in each figure, three mutually orthogonal axes are alsoreferred to as an X axis, a Y axis, and a Z axis, respectively, adirection parallel to the X axis is also referred to as an “X-axisdirection”, a direction parallel to the Y axis is also referred to as an“Y-axis direction”, and a direction parallel to the Z axis is alsoreferred to as a “Z-axis direction”. In addition, a tip side of eachaxis in an arrow direction is also referred to as a “plus side”, and anopposite side is also referred to as a “minus side”.

In a specification of the present application, a term “orthogonal”includes not only a case of intersecting at 90° but also a case ofintersecting at an angle (for example, 90°±5°) slightly inclined from90°. Specifically, a case where the X axis is inclined by approximately±5° with respect to a normal direction of an YZ plane, a case where theY axis is inclined by approximately ±5° with respect to a normaldirection of an XZ plane, and a case where the Z axis is inclined byapproximately ±5° with respect to the normal direction of the XY planeare also included in the “orthogonal”.

A physical quantity sensor 1 illustrated in FIG. 1 is a two-axisacceleration sensor capable of detecting an acceleration Ax in theX-axis direction and an acceleration Ay in the Y-axis direction. Thephysical quantity sensor 1 includes a substrate 2, elements 3, 4, 5 and6 provided on the substrate 2, a lid 10 joined to the substrate 2 so asto cover the respective elements 3, 4, 5, and 6. Among the four elements3, 4, 5, and 6, the elements 3 and 4 are elements for detecting theacceleration Ax, and the elements 5 and 6 are elements for detecting theacceleration Ay.

As illustrated in FIG. 1, the substrate 2 has a plate shape of arectangular plan view shape. In addition, the substrate 2 has a recessedportion 21 formed on an upper surface thereof. In a plan view from theZ-axis direction, the recessed portion 21 is formed so as to includemovable portions 34, 44, 54, 64 of the elements 3, 4, 5, 6 inside. Therecessed portion 21 functions as a relief portion for preventing themovable portions 34, 44, 54, 64 from coming into contact with thesubstrate 2. The plan view shape of the substrate 2 is not limited inparticular, and may be any shape such as a triangle, a quadrangle otherthan a rectangle, a polygon such as a pentagon, a circle, an ellipse, oran irregular shape.

In addition, the substrate 2 includes five grooves 25, 26, 27, 28, and29 formed on the upper surface. One end of each of the grooves 25, 26,27, 28, and 29 is located outside the lid 10.

A glass substrate formed of, for example, a glass material containingalkali metal ions (movable ions) (for example, Pyrex glass (registeredtrademark) or borosilicate glass such as Tempax glass (registeredtrademark)) can be used as the substrate 2 described above. Thereby, aswill be described below, the element 3 and the substrate 2 can be bondedby anodic bonding and can be firmly bonded. In addition, since thesubstrate 2 having light transmittance is obtained, a state of theelement 3 can be visually recognized from the outside of the physicalquantity sensor 1 via the substrate 2.

However, the substrate 2 is not limited to the glass substrate, and forexample, a silicon substrate or a ceramic substrate may be used. In acase where the silicon substrate is used, a high resistance siliconsubstrate is used from the viewpoint of preventing a short circuit, butit is preferable to use a silicon substrate having a silicon oxide film(insulating oxide) formed on a surface thereof by thermal oxidation orthe like.

In addition, as illustrated in FIG. 1, wires 71, 72, 73, 74, and 75 areprovided in the grooves 25, 26, 27, 28, and 29. In addition, one end ofeach of the wires 71, 72, 73, 74, and 75 is exposed to the outside ofthe lid 10, and function as a terminal T that is electrically connectedto an external device. Portions at which the wires 71, 72, 73, 74, and75 intersect are insulated.

A configuration material of the wires 71, 72, 73, 74, 75 is not limitedin particular, and, for example, metal materials such as gold (Au),silver (Ag), platinum (Pt), palladium (Pd), iridium (Ir), copper (Cu),aluminum (Al), nickel (Ni), titanium (Ti), and tungsten (W), an alloycontaining the metal materials, an oxide-based transparent conductivematerial such as indium tin oxide (ITO), indium zinc oxide (IZO), ZnO,or IGZO, or the like can be used as the wire, and one kind oracombination of two or more of these (for example, as a stacking body oftwo or more layers) can be used for the wire.

In addition, the lid 10 has a plate shape of a rectangular plan viewshape. In addition, as illustrated in FIG. 2, the lid 10 includes arecessed portion 11 which opens on a lower surface side. In addition,the lid 10 is formed so as to store the elements 3, 4, 5, 6 in therecessed portion 11, and is bonded to the upper surface of the substrate2. In FIG. 2, illustration of the grooves 25, 26, 27, 28, 29 and thewires 71, 72, 73, 74, 75 is omitted for the sake of convenientdescription. The lid 10 and the substrate 2 form a storage space S inwhich the elements 3, 4, 5, 6 are stored. However, the plan view shapeof the lid 10 is not limited in particular, is determined according tothe plan view shape of the substrate 2, and may be any shape such as atriangle, a quadrangle other than a rectangle, a polygon such as apentagon, a circle, an ellipse, or an irregular shape.

As illustrated in FIG. 2, the lid 10 includes a communication hole 12that communicates between the inside and the outside of the storagespace S and can change the storage space S into a desirable atmospherevia the communication hole 12. In addition, a sealing 13 is disposed inthe communication hole 12, and the communication hole 12 is sealed bythe sealing 13.

The sealing 13 is not limited in particular as long as the sealing canseal the communication hole 12, and, for example, various alloys suchas, a gold (Au)/tin (Sn)-based alloy, a gold (Au)/germanium (Ge)-basedalloy, and a gold (Au)/Aluminum (Al)-based alloy, a glass material suchas low melting point glass, and the like can be used as the sealing.

It is preferable that the storage space S stores an inert gas such asnitrogen, helium, or argon and is substantially at atmospheric pressureat an operating temperature (approximately −40° C. to 80° C.). Bysetting the storage space S to the atmospheric pressure, a viscousresistance increases, a damping effect is exerted, and vibration of theelements 3, 4, 5, and 6 can be promptly converged (stopped).Accordingly, detection accuracy of the accelerations Ax and Ay of thephysical quantity sensor 1 is increased.

In the present embodiment, the lid 10 is configured with a siliconsubstrate. However, the lid 10 is not limited to the silicon substrate,and for example, a glass substrate or a ceramic substrate may be usedtherefor. In addition, a bonding method between the substrate 2 and thelid 10 is not limited in particular, and may be appropriately selecteddepending on materials of the substrate 2 and the lid 10, but, forexample, anodic bonding, activation bonding for bonding junctionsurfaces activated by plasma irradiation, bonding made by a bondingmaterial such as glass frit, diffusion bonding for bonding metal filmsformed on an upper surface of the substrate 2 and a lower surface of thelid 10, and the like may be used therefor.

In the present embodiment, as illustrated in FIG. 2, the substrate 2 andthe lid 10 are bonded to each other via a glass frit 19 (low meltingpoint glass) which is an example of a bonding material. In a state wherethe substrate 2 and the lid 10 are overlapped with each other, theinside and outside of the storage space S communicate with each othervia the grooves 25, 26, 27, 28, and 29. Therefore, by using the glassfrit 19, the substrate 2 and the lid 10 can be bonded to each other andthe grooves 25, 26, 27, 28, and 29 can be sealed. Accordingly, airtightsealing of the storage space S becomes easy. In a case where thesubstrate 2 and the lid 10 are bonded to each other by anodic bonding orthe like (that is, a bonding method that cannot seal the grooves 25, 26,27, 28, and 29), the grooves 25, 26, 27, 28, and 29 can be closed by anSiO₂ film formed by a CVD method or the like that uses, for example,tetraethoxysilane (TEOS).

The elements 3, 4, 5, and 6 will be described. As described above, amongthe elements, the elements 3 and 4 are elements for detecting theacceleration Ax in the X-axis direction, and the elements 5 and 6 areelements for detecting the acceleration Ay in the Y-axis direction.

The elements 3, 4, 5, and 6 are formed by patterning a silicon substratedoped with impurities such as phosphorus (P) or boron (B) by etching(particularly dry etching). In addition, each of the elements 3, 4, 5, 6is bonded to the substrate 2 by anodic bonding. However, materials ofthe elements 3, 4, 5, and 6 and a bonding method of the elements 3, 4,5, and 6 to the substrate 2 are not limited in particular.

Here, as illustrated in FIG. 3, a first virtual line Lx in the X-axisdirection and a second virtual line Ly intersecting the first virtualline Lx in the Y-axis direction are set. An intersection point O of thefirst virtual line Lx and the second virtual line Ly is locatedsubstantially at the center of the recessed portion 21 in a plan viewfrom the Z-axis direction. Furthermore, among four quadrants partitionedby the first virtual line Lx and the second virtual line Ly, one set ofquadrants facing the intersection point O is referred to as a firstquadrant E1 (a region on a plus side in the X axis and a minus side inthe Y axis) and a second quadrant E2 (a region on a minus side in the Xaxis and a minus side of Y axis) and the other set of quadrants isreferred to as a third quadrant E3 (a region on the minus side in the Xaxis and the plus side in the Y axis) and a fourth quadrant E4 (a regionon the plus side in the X-axis and the minus side in the Y-axis). In thepresent embodiment, the element 3 is disposed in the first quadrant E1,the element 4 is disposed in the second quadrant E2, the element 5 isdisposed in the third quadrant E3, and the element 5 is disposed in thefourth quadrant E4. With the dispositions, the four elements 3, 4, 5,and 6 can be efficiently disposed at a smaller space. Accordingly, it ispossible to reduce a size of the physical quantity sensor 1.

As illustrated in FIG. 1, the element 3 includes a first fixingelectrode 31 and a second fixing electrode 32 which are fixed to thesubstrate 2, a fixing portion 33 fixed to the substrate 2, a movableportion 34 which is displaceable in the X-axis direction with respect tothe fixing portion 33, a spring 35 connecting the fixing portion 33 tothe movable portion 34, and a first movable electrode 36 and a secondmovable electrode 37 which are provided in the movable portion 34. Amongthose, the fixing portion 33, the movable portion 34, the spring 35, andthe first and second movable electrodes 36 and 37 are integrally formed,and hereinafter, the aggregate will be referred to as a “movable body30”.

The fixing portion 33 has an elongated shape extending in the X-axisdirection and includes a bonding pad 331 bonded to an upper surface ofthe substrate 2 at an end on the plus side in the X-axis direction. Thefixing portion 33 has a function of supporting the movable portion 34.In addition, the fixing portion 33 is located at a central portion ofthe element 3, and thereby, the movable portion 34 can be stablysupported.

The movable portion 34 has a substantially “U” shape surrounding thefixing portion 33 from three sides in a plan view in the Z-axisdirection. Specifically, the movable portion 34 includes a firstextension portion 341 which is located on the minus side in the X-axisdirection with respect to the fixing portion 33 and extends in theY-axis direction, a second extension portion 342 which is located on theplus side in the Y-axis direction with respect to the fixing portion 33and extends in the X-axis direction, and a third extension portion 343which is located on the minus side in the Y-axis direction with respectto the fixing portion 33 and extends in the X-axis direction. Asdescribed above, it can also be said that the movable portion 34 has aframe shape having an opening on the plus side in the X-axis direction.By making the movable portion 34 have such a shape, it is possible toincrease a mass of the movable portion 34. Accordingly, sensitivity isincreased, and the acceleration Ax can be detected accurately.

In addition, a gap 381 for disposing the first fixing electrode 31 andthe first movable electrode 36 is formed between the second extensionportion 342 and the fixing portion 33, and a gap 382 for disposing thesecond fixing electrode 32 and the second movable electrode 37 is formedbetween the third extension portion 343 and the fixing portion 33.

In addition, the spring 35 is elastically deformable in the X-axisdirection, and as the movable portion 34 is elastically deformed, themovable portion 34 can be displaced in the X-axis direction with respectto the fixing portion 33. The spring 35 connects an end of the fixingportion 33 on the minus side in the X-axis direction to the firstextension portion 341 of the movable portion 34. Accordingly, themovable portion 34 is cantilever-supported (supported on only one sidewith respect to the center of the movable portion 34) to the fixingportion 33 via the spring 35. By cantilever-supporting the movableportion 34, a size of the element 3 can be reduced, for example,compared with a case where the movable portion 34 is supported at bothends by a pair of springs 35.

The first fixing electrode 31 includes a fixing portion 311 fixed to thesubstrate 2, a trunk 312 extending to the minus side in the X-axisdirection from the fixing portion 311, and a plurality of fixingelectrode fingers 313 extending to the plus side in the Y-axis directionfrom the trunk 312. Among those, each of the trunks 312 and the fixingelectrode fingers 313 is located in a gap 381. In addition, the fixingportion 311 is located on the plus side in the Y-axis direction withrespect to the fixing portion 33, and is juxtaposed with the fixingportion 33. In addition, the fixing portion 311 includes a bonding pad311 a bonded to the substrate 2. In addition, the plurality of fixingelectrode fingers 313 are arranged side by side in the X-axis directionat approximately equal intervals.

Likewise, the second fixing electrode 32 includes a fixing portion 321fixed to the substrate 2, a trunk 322 extending to the minus side in theX-axis direction from the fixing portion 321, and a plurality of fixingelectrode fingers 323 extending in the Y-axis direction of the Y-axisdirection from the trunk 322. Among those, each of the trunk 322 and thefixing electrode fingers 323 is located in a gap 382. In addition, thefixing portion 321 is located on the minus side in the Y-axis directionwith respect to the fixing portion 33 and is juxtaposed with the fixingportion 33. In addition, the fixing portion 321 includes a bonding pad321 a bonded to the substrate 2. In addition, the plurality of fixingelectrode fingers 323 are arranged side by side in the X-axis directionat approximately equal intervals.

The first movable electrode 36 includes a plurality of movable electrodefingers 361 which are arranged in the gap 381 and arranged side by sidein the X-axis direction. In addition, the plurality of movable electrodefingers 361 respectively extend from the second extension portion 342toward the minus side in the Y-axis direction, and are located on theplus side in the X-axis direction with respect to the correspondingfixing electrode finger 313, and face each other. As will be describedbelow, while the physical quantity sensor 1 is driven, an electrostaticcapacitance is formed between the movable electrode finger 361 and thefixing electrode finger 313 which form a pair.

Likewise, the second movable electrode 37 includes a plurality ofmovable electrode fingers 371 which are located in the gap 382 and arearranged side by side in the X-axis direction. In addition, theplurality of movable electrode fingers 371 respectively extend from thethird extension portion 343 toward the plus side in the Y-axisdirection, are located on the minus side in the X-axis direction withrespect to the corresponding fixing electrode finger 323, and face eachother. As will be described below, while the physical quantity sensor 1is driven, an electrostatic capacitance is formed between the movableelectrode finger 371 and the fixing electrode finger 323 that form apair.

The element 4 has the same configuration as the element 3 describedabove and is disposed on the substrate 2 in a state of being rotated by180° around the intersection point O with respect to the element 3. Thatis, the element 4 is provided point-symmetrically with the element 3with respect to the intersection point O.

The element 4 includes a first fixing electrode 41 and a second fixingelectrode 42 which are fixed to the substrate 2, a fixing portion 43fixed to the substrate 2, a movable portion 44 that is displaceable inthe X-axis direction with respect to the fixing portion 43, a spring 45connecting the fixing portion 43 to the movable portion 44, and a firstmovable electrode 46 and a second movable electrode 47 which areprovided in the movable portion 44. Among those, the fixing portion 43,the movable portion 44, the spring 45, and the first and second movableelectrodes 46, 47 are integrally formed, and hereinafter, the aggregatewill be also referred to as a “movable body 40”.

Since the element 4 has the same configuration as the element 3, theelement 4 will be briefly described hereinafter (for the detailedconfiguration, refer to the description on the element 3).

The fixing portion 43 has an elongated shape extending in the X-axisdirection and includes a bonding pad 431 with the substrate 2 at an endon the minus side in the X-axis direction. The movable portion 44 has asubstantially “U” shape surrounding the fixing portion 33 from threesides in a plan view in the Z-axis direction, and includes a firstextension portion 441, a second extension portion 442, and a thirdextension portion 443. In addition, a gap 481 for disposing the firstfixing electrode 41 and the first movable electrode 46 is formed betweenthe second extension portion 442 and the fixing portion 43, and a gap482 for disposing the second fixing electrode 42 and the second movableelectrode 47 is formed between the third extension portion 443 and thefixing portion 43.

The spring 45 connects an end of the fixing portion 43 on the plus sidein the X-axis direction to the first extension portion 441 of themovable portion 44. Accordingly, the movable portion 44 iscantilever-supported by the fixing portion 43 via the spring 45.

The first fixing electrode 41 includes a fixing portion 411 including abonding pad 411 a with the substrate 2, a trunk 412 extending from thefixing portion 411 toward the plus side in the X-axis direction, and aplurality of fixing electrode fingers 413 extending from the trunk 412toward the minus side in the Y-axis direction. In addition, the secondfixing electrode 42 includes a fixing portion 421 including a bondingpad 421 a with the substrate 2, a trunk 422 extending from the fixingportion 421 toward the plus side in the X-axis direction, and aplurality of fixing electrode fingers 423 extending from the trunk 422on the plus side in the Y-axis direction.

The first movable electrode 46 includes a plurality of movable electrodefingers 461 which are located in the gap 481 and are arranged side byside in the X-axis direction. The plurality of movable electrode fingers461 extend from the second extension portion 442 toward the plus side inthe Y-axis direction, are each located on the minus side in the X-axisdirection with respect to the corresponding fixing electrode finger 413,and face each other. In addition, the second movable electrode 47includes a plurality of movable electrode fingers 471 which are locatedin the gap 482 and are arranged side by side in the X-axis direction.The plurality of movable electrode fingers 471 extend from the thirdextension portion 443 toward the minus side in the Y-axis direction, arerespectively located on the plus side in the X-axis direction withrespect to the corresponding fixing electrode fingers 423, and face eachother.

The element 5 has the same configuration as the above-described element3, and is disposed on the substrate 2 in a state of being rotated by 90°counterclockwise in FIG. 1 around the intersection point O with respectto the element 3. That is, the element 5 is providedrotation-symmetrically with respect to the element 3 with respect to theintersection point O.

The element 5 includes a first fixing electrode 51 and a second fixingelectrode 52 which are fixed to the substrate 2, a fixing portion 53fixed to the substrate 2, a movable portion 54 displaceable in theY-axis direction with respect to the fixing portion 53, a spring 55connecting the fixing portion 53 to the movable portion 54, and a firstmovable electrode 56 and a second movable electrode 57 which areprovided in the movable portion 54. Among those, the fixing portion 53,the movable portion 54, the spring 55, and the first and second movableelectrodes 56 and 57 are integrally formed, and hereinafter, theaggregate is also referred to as a “movable body 50”.

Since the element 5 has the same configuration as the element 3, theelement 5 will be briefly described below (for the detailedconfiguration, refer to the description on the element 3).

The fixing portion 53 has an elongated shape extending in the Y-axisdirection and includes a bonding pad 531 with the substrate 2 at an endon the plus side in the Y-axis direction. The movable portion 54 has asubstantially “U” shape surrounding the fixing portion 53 from threesides in a plan view in the Z-axis direction, and includes a firstextension portion 541, a second extension portion 542, and a thirdextension portion 543. In addition, a gap 581 for disposing the firstfixing electrode 51 and the first movable electrode 56 is formed betweenthe second extension portion 542 and the fixing portion 53, and a gap582 for disposing the second fixing electrode 52 and the second movableelectrode 57 is formed between the third extension portion 543 and thefixing portion 53.

The spring 55 connects an end of the fixing portion 53 on the minus sidein the Y-axis direction to the first extension portion 541 of themovable portion 54. Accordingly, the movable portion 54 iscantilever-supported by the fixing portion 53 via the spring 55.

The first fixing electrode 51 includes a fixing portion 511 including abonding pad 511 a with the substrate 2, a trunk 512 extending from thefixing portion 511 toward the minus side in the Y-axis direction, and aplurality of fixing electrode fingers 513 extending from the trunk 512toward the minus side in the X-axis direction. In addition, the secondfixing electrode 52 includes a fixing portion 521 including a bondingpad 521 a with the substrate 2, a trunk 522 extending from the fixingportion 521 toward the minus side in the Y-axis direction, and aplurality of fixing electrode fingers 523 extending from the trunk 522toward the plus side in the X-axis direction.

The first movable electrode 56 includes a plurality of movable electrodefingers 561 which are located in the gap 581 and are arranged side byside in the Y-axis direction. The plurality of movable electrode fingers561 extend from the second extension portion 542 toward the plus side inthe X-axis direction, are respectively located on the plus side in theY-axis direction with respect to the corresponding fixing electrodefinger 513, and face each other. In addition, the second movableelectrode 57 includes a plurality of movable electrode fingers 571 whichare located in the gap 582 and are arranged side by side in the Y-axisdirection. The plurality of movable electrode fingers 571 extend fromthe third extension portion 543 toward the minus side in the X-axisdirection, are respectively located on the minus side in the Y-axisdirection with respect to the corresponding fixing electrode finger 523,and face each other.

The element 6 has the same configuration as the above-described element3, and is disposed in the substrate 2 in a state of being rotated by 90°clockwise in FIG. 1 around the intersection point O with respect to theelement 3 described above. That is, the element 6 is providedrotation-symmetrically with respect to the element 3 with respect to theintersection point O.

The element 6 includes a first fixing electrode 61 and a second fixingelectrode 62 which are fixed to the substrate 2, a fixing portion 63fixed to the substrate 2, a movable portion 64 which is displaceable inthe Y-axis direction with respect to the fixing portion 63, a spring 65connecting the fixing portion 63 to the movable portion 64, and a firstmovable electrode 66 and a second movable electrode 67 which areprovided in the movable portion 64. Among those, the fixing portion 63,the movable portion 64, the spring 65, and the first and second movableelectrodes 66 and 67 are integrally formed, and hereinafter, theaggregate will be also referred to as a “movable body 60”.

Since the element 6 has the same configuration as the element 3, theelement 6 will be briefly described below (for a detailed configuration,refer to the description on the element 3).

The fixing portion 63 has an elongated shape extending in the Y-axisdirection and includes a bonding pad 631 with the substrate 2 at an endon the minus side in the Y-axis direction. The movable portion 64 has asubstantially “U” shape surrounding the fixing portion 63 from threesides in a plan view in the Z-axis direction, and includes a firstextension portion 641, a second extension portion 642, and a thirdextension portion 643. In addition, a gap 681 for disposing the firstfixing electrode 61 and the first movable electrode 66 is formed betweenthe second extension portion 642 and the fixing portion 63, and a gap682 for disposing the second fixing electrode 62 and the second movableelectrode 67 is formed between the third extension portion 643 and thefixing portion 63.

The spring 65 connects an end of the fixing portion 63 on the plus sidein the Y-axis direction to the first extension portion 641 of themovable portion 64. Accordingly, the movable portion 64 iscantilever-supported by the fixing portion 63 via the spring 65.

The first fixing electrode 61 includes a fixing portion 611 including abonding pad 611 a with the substrate 2, a trunk 612 extending from thefixing portion 611 toward the plus side in the Y-axis direction, and aplurality of fixing electrode fingers 613 extending from the trunk 612toward the plus side in the X-axis direction. In addition, the secondfixing electrode 62 includes a fixing portion 621 including a bondingpad 621 a with the substrate 2, a trunk 622 extending from the fixingportion 621 toward the plus side in the Y-axis direction, and aplurality of fixing electrode fingers 623 extending from the trunk 622toward the minus side in the X-axis direction.

The first movable electrode 66 includes a plurality of movable electrodefingers 661 which are located in the gap 681 and are arranged side byside in the Y-axis direction. The plurality of movable electrode fingers661 extend from the second extension portion 642 toward the minus sidein the X-axis direction, are respectively located on the minus side inthe Y-axis direction with respect to the corresponding fixing electrodefinger 613, and face each other. In addition, the second movableelectrode 67 includes a plurality of movable electrode fingers 671 whichare located in the gap 682 and are arranged side by side in the Y-axisdirection. The plurality of movable electrode fingers 671 extends fromthe third extension portion 643 toward the plus side in the X-axisdirection, are respectively located on the plus side in the Y-axisdirection with respect to the corresponding fixing electrode finger 623,and face each other.

As described above, the elements 3, 4, 5, and 6 are described. Among theelements 3, 4, 5, and 6, the movable bodies 30, 40, 50, and 60 areelectrically connected to the wire 71 via the fixing portions 33, 43,53, and 63, respectively. In addition, the first fixing electrode 31 andthe second fixing electrode 42 are electrically connected to the wire 72via the fixing portions 311 and 421, respectively. In addition, thesecond fixing electrode 32 and the first fixing electrode 41 areelectrically connected to the wire 73 via the fixing portions 321 and411, respectively. In addition, the first fixing electrode 51 and thesecond fixing electrode 62 are electrically connected to the wire 74 viathe fixing portions 511 and 621, respectively. In addition, the secondfixing electrode 52 and the first fixing electrode 61 are electricallyconnected to the wire 75 via the fixing portions 521 and 611,respectively.

In addition, when the physical quantity sensor 1 is in operation, forexample, a voltage V1 of FIG. 5 is applied to the wire 71 and a voltageV2 of FIG. 5 is applied to the wires 72, 73, 74, and 75. Accordingly, inthe element 3, an electrostatic capacitance C31 is formed between themovable electrode finger 361 and the fixing electrode finger 313 whichform a pair, and an electrostatic capacitance C32 is formed between themovable electrode finger 371 and the fixing electrode finger 323 whichform a pair. In addition, in the element 4, an electrostatic capacitanceC41 is formed between the movable electrode finger 461 and the fixingelectrode finger 413 which form a pair, and an electrostatic capacitanceC42 is formed between the movable electrode finger 471 and the fixingelectrode finger 423 which form a pair. In addition, in the element 5,an electrostatic capacitance C51 is formed between the movable electrodefinger 561 and the fixing electrode finger 513 which form a pair, and anelectrostatic capacitance C52 is formed between the movable electrodefinger 571 and the fixing electrode finger 523 which form a pair. Inaddition, in the element 6, an electrostatic capacitance C61 is formedbetween the movable electrode finger 661 and the fixing electrode finger613 which form a pair, and an electrostatic capacitance C62 is formedbetween the movable electrode finger 671 and the fixing electrode finger623 which form a pair.

If the acceleration Ax acts on the physical quantity sensor 1 on theplus side in the X-axis direction, the element 3 is displaced on theminus side in the X-axis direction with respect to the fixing portion33, based on a magnitude of the acceleration Ax, while the movableportion 34 elastically deforms the spring 35. Accordingly, a gap betweenthe movable electrode finger 361 and the fixing electrode finger 313 isreduced to increase the electrostatic capacitance C31 therebetween, andin contrast to this, a gap between the movable electrode finger 371 andthe fixing electrode finger 323 is widened to reduce the electrostaticcapacitance C32 therebetween. Meanwhile, the element 4 is displaced onthe minus side in the X-axis direction with respect to the fixingportion 43 while the movable portion 44 elastically deforms the spring45. Accordingly, a gap between the movable electrode finger 471 and thefixing electrode finger 423 is reduced to increase the electrostaticcapacitance C42 therebetween, and in contrast to this, a gap between themovable electrode finger 461 and the fixing electrode finger 413 iswidened to reduce the electrostatic capacitance C41 therebetween.Changes in the electrostatic capacitances C31 and C42 are output fromthe wire 72 as a first X-axis detection signal, and changes of theelectrostatic capacitances C32 and C41 are output from the wire 73 as asecond X-axis detection signal. The first X-axis detection signal andthe second X-axis detection signal are differentially calculated, and itis possible to detect the acted acceleration Ax, based on thecalculation result.

In a case where the acceleration Ax acts on the physical quantity sensor1 on the minus side in the X-axis direction, an operation opposite tothe above description is performed. Accordingly, a detailed descriptionthereof will be omitted.

If the acceleration Ay acts on the physical quantity sensor 1 on theplus side in the Y-axis direction, the element 5 is displaced on theminus side in the Y-axis direction with respect to the fixing portion53, based on a magnitude of the acceleration Ay, while the movableportion 54 elastically deforms the spring 55. Accordingly, a gap betweenthe movable electrode finger 561 and the fixing electrode finger 513 isreduced to increase the electrostatic capacitance C51 therebetween, andin contrast to this, a gap between the movable electrode finger 571 andthe fixing electrode finger 523 is widened to reduce the electrostaticcapacitance C52 therebetween. Meanwhile, the element 6 is displaced onthe minus side in the X-axis direction with respect to the fixingportion 63 while the movable portion 64 elastically deforms the spring65. Accordingly, a gap between the movable electrode finger 671 and thefixing electrode finger 623 is reduced to increase the electrostaticcapacitance C62 therebetween, and in contrast to this, a gap between themovable electrode finger 661 and the fixing electrode finger 613 iswidened to reduce the electrostatic capacitance C61 therebetween.Changes of the capacitances C51 and C62 are output from the wire 74 as afirst Y-axis detection signal, and changes of the capacitances C52 andC61 are output from the wire 75 as a second Y-axis detection signal. Thefirst Y-axis detection signal and the second Y-axis detection signal aredifferentially calculated, and it is possible to detect the actedacceleration Ay, based on the calculation result.

If the acceleration acts on the physical quantity sensor 1 Ax on theminus side in the Y-axis direction, an operation opposite to the abovedescription is performed. Accordingly, a detailed description thereofwill be omitted.

As described above, the physical quantity sensor 1 can detect theacceleration Ax in the X-axis direction and the acceleration Ay in theY-axis direction. Even if the acceleration Ax acts, each of theelectrostatic capacitances C51 and C52 of the element 5 and theelectrostatic capacitances C61 and C62 of the element 6 does notsubstantially change. Accordingly, the elements 5 and 6 are not used fordetecting the acceleration Ax. Likewise, even if the acceleration Ayacts, the electrostatic capacitances C31 and C32 of the element 3 andthe electrostatic capacitances C41 and C42 of the element 4 do notsubstantially change. Accordingly, the elements 3 and 4 are not used fordetecting the acceleration Ay. In this way, the elements 3 and 4 areused for detecting the acceleration Ax and the elements 5 and 6 are usedfor detecting the acceleration Ay, and thereby, the physical quantitysensor 1 can simultaneously detect the acceleration Ax and theacceleration Ay.

Very excellent advantages of the physical quantity sensor 1 will bedescribed. As illustrated in FIG. 1, in the physical quantity sensor 1,bonding pads with the substrate 2 are collectively arranged in one placein a relatively narrow region for each of the elements 3, 4, 5, and 6.Accordingly, the following effects can be exerted.

The element 3 will be Representatively described. The fixing portions33, 311, and 321 are collectively arranged in one place. Specifically,the fixing portions 33, 311, and 321 are arranged side by side in theY-axis direction, and the fixing portions 311 and 321 are located onboth sides with the fixing portion 33 interposed therebetween. That is,other structure bodies are not located between the fixing portion 33 andthe fixing portion 311 and between the fixing portion 33 and the fixingportion 321, respectively. According to the arrangement, the bondingpads 311 a and 321 a of the fixing portions 311 and 321 can be arrangednear the bonding pad 331 of the fixing portion 33. Accordingly, it ispossible to suppress influence of heat deflection (warpage or deflectioncaused by heat) of the substrate 2 to a small level, and to exertexcellent temperature characteristics.

More specifically, as illustrated in FIG. 6, even if heat deflection ofthe substrate 2 occurs, shifting of the fixing electrode finger 313 fromthe movable electrode finger 361 is substantially equal to shifting ofthe fixing electrode finger 323 from the movable electrode finger 371.Accordingly, although magnitudes of the electrostatic capacitances C31and C32 change due to the heat deflection of the substrate 2, adifference |C31−C32| does not substantially change. As described above,since the acceleration Ax is detected based on the difference betweenthe electrostatic capacitances C31 and C32, the change in the differencebetween the electrostatic capacitances C31 and C32 due to the heatdeflection (that is, a factor other than the acceleration Ax) of thesubstrate 2 is suppressed, and thereby, excellent temperaturecharacteristics are exerted and the acceleration Ax can be detectedaccurately.

A separation distance between the fixing portion 33 and the fixingportion 311 and a separation distance D1 (see FIG. 4) between the fixingportion 33 and the fixing portion 321 are not limited in particular, andare preferably greater than or equal to 1 μm and smaller than or equalto 10 μm, for example. Thereby, the fixing portions 311 and 321 can bearranged sufficiently close to the fixing portion 33. In addition, adistance D2 (see FIG. 4) between an end of the fixing portion 311 on theplus side in the Y-axis direction and an end of the fixing portion 321on the minus side in the Y-axis direction are not limited in particular,and are preferably greater than or equal to approximately 50 μm andsmaller than or equal to approximately 300 μm, for example. Thereby, theabove-described effects can be exerted more reliably, and a bondingstrength of the fixing portions 33, 311, and 321 to the substrate 2 canbe sufficiently kept high.

In addition, as described above, in the physical quantity sensor 1, theelements 3 and 4 are arranged point-symmetrically to the intersectionpoint O, and the elements 5 and 6 are arranged point-symmetrically tothe intersection point O. Accordingly, the following effects can beexerted.

As described above, in the elements 3, 4, 5, 6, the movable portions 34,44, 54, and 64 are cantilever-supported to the fixing portions 33, 43,53, and 63 via the springs 35, 45, 55, and 65. Accordingly, while a sizeof the physical quantity sensor 1 is reduced, vibration (unnecessaryvibration other than detected vibration) of a rotation system around theZ axis is likely to occur in the movable portions 34, 44, 54, and 64. Ifthe vibration of the rotation system occurs in the movable portions 34,44, 54, and 64, the electrostatic capacitances C31, C32, C41, C42, C51,C52, C61, and C62 are changed, and detection accuracy of theaccelerations Ax and Ay decreases. However, the physical quantity sensor1 can suppress a decrease in detection accuracy of the accelerations Axand Ay due to the unnecessary vibration. That is, the physical quantitysensor 1 can detect the accelerations Ax and Ay with high accuracy and asize thereof can be reduced.

Specifically, as illustrated in FIG. 7, if an angular velocity ωz aroundthe Z axis acts on the physical quantity sensor 1, the movable portions34, 44, 54, and 64 are displaced around the Z axis with respect to thefixing portions 33, 43, 53, and 63 in the same manner.

If the angular velocity ωz acts, the gap between the fixing electrodefinger 313 and the movable electrode finger 361, the gap between thefixing electrode finger 323 and the movable electrode finger 371, thegap between the fixing electrode finger 413 and the movable electrodefinger 461, and the gap between the fixing electrode finger 423 and themovable electrode finger 471 are all reduced or all widened (widened inFIG. 7), in the element 3 and the element 4 that detect the accelerationAx. The reducing and the widening are substantially the same. That is,the electrostatic capacitances C31, C32, C41, and C42 are all increasedby the same amount, or are all reduced by the same amount. Accordingly,although the angular velocity ωz acts, a difference between the firstX-axis detection signal taken out from the wire 72 and the second X-axisdetection signal taken out from the wire 73 is not substantially changedcompared to a state in which the angular velocity ωz does not act. Thus,even in a state where the angular velocity ωz is applied, theacceleration Ax can be accurately detected.

Likewise, if the angular velocity ωz acts, the gap between the fixingelectrode finger 513 and the movable electrode finger 561, the gapbetween the fixing electrode finger 523 and the movable electrode finger571, the gap between the electrode finger 613 and the movable electrodefinger 661, and the gap between the fixing electrode finger 623 and themovable electrode finger 671 are all reduced or all widened (widened inFIG. 7), in the element 5 and the element 6 that detect the accelerationAy. The reducing and the widening are substantially the same. That is,the electrostatic capacitances C51, C52, C61, and C62 are all increasedby the same amount, or are all reduced by the same amount. Accordingly,although the angular velocity ωz acts, a difference between the firstY-axis detection signal taken out from the wire 74 and the second Y-axisdetection signal taken out from the wire 75 is not substantially changedcompared to a state where the angular velocity ωz does not act. Thus,even in a state where the angular velocity ωz is applied, theacceleration Ay can be accurately detected.

As described above, according to the physical quantity sensor 1, it ishard to be influenced by the angular velocity ωz, and it is possible todetect the accelerations Ax and Ay with high accuracy and to reduce asize of an apparatus.

The physical quantity sensor 1 is described above in detail. Asdescribed above, the physical quantity sensor 1 includes the substrate2, a pair of elements 3 and 4 (first element) which are located on thesubstrate 2 and detect the acceleration Ax in the X-axis direction(first direction), and a pair of elements 5 and 6 (second element) whichare located on the substrate 2 and detect the acceleration Ay in theY-axis direction (second direction) orthogonal to the X-axis direction.The elements 3 and 4 includes the movable portions 34 and 44 (firstmovable portion) which are displaceable in the X-axis direction withrespect to the substrate 2, the movable electrode fingers 361 and 471(first movable electrode fingers) and movable electrode fingers 471 and461 (second movable electrode fingers) which are disposed on the movableportions 34 and 44, the fixing electrode fingers 313 and 423 (firstfixing electrode fingers) which are arranged on the minus side (oneside) of the X-axis direction with respect to the movable electrodefingers 361 and 471, the fixing portions 311 and 421 (first supportportions) which are fixed to the substrate 2 and support the fixingelectrode fingers 313 and 423, the fixing electrode fingers 323 and 413(second fixing electrode fingers) which are arranged on the plus side(the other side) of the X-axis direction with respect to the movableelectrode fingers 371 and 461, and the fixing portions 321 and 411(second support portions) which are fixed to the substrate 2, arejuxtaposed with the fixing portions 311 and 421, and support the fixingelectrode fingers 323 and 413, respectively. In addition, the elements 5and 6 include the movable portions 54 and 64 (second movable portions)displaceable in the Y-axis direction with respect to the substrate 2,the movable electrode fingers 561 and 671 (third movable electrodefinger) and the movable electrode fingers 571 and 661 (fourth movableelectrode fingers) which are arranged in the movable portions 54 and 64,the fixing electrode fingers 513 and 623 (third fixing electrodefingers) arranged on the minus side (one side) of the Y-axis directionwith respect to the movable electrode fingers 561 and 671, the fixingportions 511 and 621 (third support portions) which are fixed to thesubstrate 2 and support the fixing electrode fingers 513 and 623, thefixing electrode fingers 523 and 613 (fourth fixing electrode fingers)disposed on the plus side (the other side) of the Y-axis direction withrespect to the movable electrode fingers 571 and 661, and the fixingportions 521 and 611 (fourth support portion) which are fixed to thesubstrate 2, juxtaposed with the fixing portions 511 and 621, andsupport the fixing electrode fingers 523 and 613, respectively.

Accordingly, the fixing portions can be collectively arranged in anarrow region for each of the elements 3, 4, 5, and 6. That is, thefixing portions 33, 311, and 321 can be collectively arranged in anarrow area in the element 3, the fixing portions 43, 411, and 421 canbe collectively arranged in a narrow region in the element 4, the fixingportions 53, 511, and 521 can be collectively arranged in a narrow areain the element 5, and the fixing portions 63, 611, and 621 can becollectively arranged in a narrow region in the element 6. As a result,as described above, it is possible to suppress influence on the heatdeflection of the substrate 2 to a small extent, to exert excellenttemperature characteristics, and to accurately detect the accelerationsAx and Ay.

As described above, the pair of elements 3 and 4 include the fixingportions 33 and 43 (first fixing portions) fixed to the substrate 2, andthe springs 35 and 45 (first springs) connecting the fixing port ions 33and 43 to the movable portions 34 and 44, respectively. The movableportions 34 and 44 are cantilever-supported to the fixing portions 33and 43 via the springs 35 and 45. Likewise, the pair of elements 5 and 6include the fixing portions 53 and 63 (second fixing portions) fixed tothe substrate 2, and the springs 55 and 65 (second springs) connectingthe fixing portions 53 and 63 to the movable portions 54 and 64. Themovable portions 54 and 64 are cantilever-supported to the fixingportions 53 and 63 via the springs 55 and 65. Thereby, as describedabove, it is possible to reduce sizes of the elements 3, 4, 5, and 6 andto reduce a size of the physical quantity sensor 1.

In addition, as described above, if the angular velocity ωz obtained byusing the Z-axis direction (third direction) orthogonal to the X-axisdirection and the Y-axis direction as an axis is applied, the separationdistances between the movable electrode fingers 361 and 471 and thefixing electrode fingers 313 and 423, and the separation distancebetween the movable electrode fingers 371 and 461 and the fixingelectrode fingers 323 and 413 are separated from or approach each other,in the elements 3 and 4. In addition, in the elements 5, 6, theseparation distances between the movable electrode fingers 561 and 671and the fixing electrode fingers 513 and 623, and the separationdistance between the movable electrode fingers 571 and 661 and thefixing electrode fingers 523 and 613 are separated from or approach eachother. Thereby, as described above, it is hard to be influenced by theangular velocity ωz, and even in a state where the angular velocity ωzacts, the accelerations Ax and Ay can be accurately detected.

In addition, as described above, when the first virtual line Lx in theX-axis direction and the second virtual line Ly, which is orthogonal tothe first virtual line Lx, in the Y-axis direction are set, and amongthe four quadrants partitioned by the first virtual line Lx and thesecond virtual line Ly in a plan view, one set of quadrants facing eachother with respect to the intersection point O of the first virtual lineLx and the second virtual line Ly is referred to as a first quadrant E1and a second quadrant E2, and the other set is referred to as a thirdquadrant E3 and a fourth quadrant E4, one of the elements 3 and 4 isdisposed in the first quadrant E1 and the other is disposed in thesecond quadrant E2, and one of the elements 5 and 6 is disposed in thethird quadrant E3 and the other is disposed in the fourth quadrant E4.Thereby, as described above, it is possible to efficiently dispose theelements 3, 4, 5, and 6 at a smaller space. Accordingly, it is possibleto reduce a size of the physical quantity sensor 1.

In addition, as described above, the elements 3 and are disposedpoint-symmetrically with respect to the intersection point O, and theelements 5 and 6 are disposed point-symmetrically with respect to theintersection point O. Thereby, it is possible to dispose the elements 3,4, 5, and 6 in a well-balanced manner.

A configuration of the physical quantity sensor 1 is described above,the configuration of the physical quantity sensor 1 is not limited tothe present embodiment. For example, the disposition of the elements 3,4, 5, 6 is not limited in particular, and as illustrated in FIG. 8, theelement 3 may be disposed in the first quadrant E1, the element 6 may bedisposed in the second quadrant E2, the element 5 may be disposed in thethird quadrant E3, and the element 4 may be disposed in the fourthquadrant E4.

Second Embodiment

A physical quantity sensor according to a second embodiment will bedescribed.

FIG. 9 is a plan view illustrating the physical quantity sensoraccording to the second embodiment.

The physical quantity sensor 1 according to the present embodiment isthe same as the physical quantity sensor 1 according to the firstembodiment described above except that the configurations of theelements 3, 4, 5, and 6 are different.

In the following description, a difference between the physical quantitysensor 1 according to the second embodiment and the physical quantitysensor according to the first embodiment will be mainly described, anddescription on the same matters will be omitted. In addition, in FIG. 5,the same reference numerals or symbols are attached to the sameconfigurations as in the first embodiment described above.

In addition, in the present embodiment, in the same manner as in thefirst embodiment described above, the elements 3, 4, 5, and 6 areidentical in configuration and are different in orientation only, andthus, in the following description, the configuration of the element 3will be described, and the configurations of the element 4, 5, and 6will be omitted.

As illustrated in FIG. 9, in the element 3 according to the presentembodiment, the movable portion 34 has a shape that follows contours ofthe fixing portion 33 and the spring 35. A plurality of movableelectrode fingers 361 extend from the second extension portion 342toward the plus side in the Y-axis direction, and a plurality of movableelectrode fingers 371 extend from the third extension portion 343 towardthe minus side in the Y-axis direction.

In addition, in the first fixing electrode 31, the trunk 312 includes afirst portion 312 a extending from the fixing portion 311 toward theplus side in the Y-axis direction, and a second portion 312 b extendingfrom a front end of the first portion 312 a toward the minus side in theX-axis direction. In addition, the second portion 312 b is located onthe plus side in the Y-axis direction with respect to the secondextension portion 342, and the plurality of fixing electrode fingers 313extend from the second portion 312 b toward the minus side in the Y-axisdirection.

Likewise, in the second fixing electrode 32, the trunk 322 includes afirst portion 322 a extending from the fixing portion 321 to the minusside in the Y-axis direction, and a second portion 322 b extending froma front end of the first portion 322 a toward the minus side in theX-axis direction. In addition, the second portion 322 b is located onthe minus side in the Y-axis direction with respect to the thirdextension portion 343, and the plurality of fixing electrode fingers 323extend from the second portion 322 b toward the plus side in the Y-axisdirection.

Also in the second embodiment, the same effects as in the firstembodiment described above can be obtained.

Third Embodiment

A physical quantity sensor according to a third embodiment will bedescribed.

FIG. 10 is a plan view illustrating the physical quantity sensoraccording to the third embodiment.

The physical quantity sensor 1 according to the present embodiment isthe same as the physical quantity sensor 1 according to the firstembodiment described above except that the configurations of theelements 3, 4, 5, and 6 are different.

In the following description, a difference between the physical quantitysensor 1 according to the third embodiment and the physical quantitysensor according to the first embodiment will be mainly described, anddescription on the same matters will be omitted. In addition, in FIG. 5,the same reference numerals or symbols are attached to the sameconfiguration as in the first embodiment described above.

In addition, in the present embodiment, in the same manner as in thefirst embodiment described above, the elements 3, 4, 5, and 6 areidentical in configuration and are different in orientation only, andthus, in the following description, a configuration of the element 3will be representatively described and configurations of the elements 4,5, and 6 will be omitted.

As illustrated in FIG. 10, in the element 3 according to the presentembodiment, the movable portion 34 has a frame shape surrounding thefixing portion 33 and the first and second fixing electrodes 31 and 32.In addition, the spring 35 is located on the plus side in the X-axisdirection with respect to the fixing portion 33, and the first andsecond fixing electrodes 31 and 32 are located on the minus side in theX-axis direction. The fixing portions 311 and 321 are disposed side byside in the Y-axis direction, and furthermore, are disposed side by sidein the X-axis direction together with the fixing portion 33.

Also in the third embodiment, the same effects as in the firstembodiment described above can be obtained.

Fourth Embodiment

A physical quantity sensor according to a fourth embodiment will bedescribed.

FIG. 11 is a plan view illustrating the physical quantity sensoraccording to the fourth embodiment.

The physical quantity sensor 1 according to the present embodiment isthe same as the physical quantity sensor 1 according to the firstembodiment described above except that the configurations of theelements 3, 4, 5, 6 are different.

In the following description, a difference between the physical quantitysensor 1 according to the fourth embodiment and the physical quantitysensor according to the first embodiment described above will be mainlydescribed, and description on the same matters will be omitted. Inaddition, in FIG. 5, the same reference numerals or symbols are attachedto the same configurations as in the first embodiment described above.

In addition, in the present embodiment, in the same manner as in thefirst embodiment described above, the elements 3, 4, 5, and 6 areidentical in configuration and are different in orientation only, andthus, in the following description, the configuration of the element 3will be representatively described, and the configurations of theelements 4, 5, and 6 will be omitted.

As illustrated in FIG. 11, in the element 3 according to the presentembodiment, the movable portion 34 has a frame shape surrounding thefixing portion 33 and the first and second fixing electrodes 31 and 32.In addition, the fixing portion 33 extends in the Y-axis direction andincludes a bonding pad 331 at an end on the minus side in the Y-axisdirection. In addition, the spring 35 connects the movable portion 34 toan end on the plus side in the Y-axis direction with respect to thefixing portion 33.

In addition, the first fixing electrode 31 is located on the plus sidein the X-axis direction with respect to the fixing portion 33, and thesecond fixing electrode 32 is located on the minus side in the X-axisdirection. The first fixing electrode 31 includes the fixing portion311, the trunk 312 extending from the fixing portion 311 toward the plusside in the X-axis direction, and a plurality of fixing electrodefingers 313 extending from the trunk 312 on the plus side in the Y-axisdirection. In addition, the fixing portion 311 is juxtaposed with thefixing portion 33. Meanwhile, the second fixing electrode 32 includesthe fixing portion 321, the trunk 322 extending from the fixing portion321 toward the minus side in the X-axis direction, and the plurality offixing electrode fingers 323 extending from the trunk 322 toward theplus side in the Y-axis direction. In addition, the fixing portion 321is juxtaposed with the fixing portion 33 and is disposed side by side inthe Y-axis direction with the fixing portion 311 so as to interpose thefixing portion 33 therebetween.

Also in the fourth embodiment, the same effects as in the firstembodiment described above can be achieved.

Fifth Embodiment

A physical quantity sensor device according to a fifth embodiment of theinvention will be described.

FIG. 12 is a cross-sectional view illustrating the physical quantitysensor device according to the fifth embodiment.

As illustrated in FIG. 12, a physical quantity sensor device 100includes the physical quantity sensor 1, a circuit element 110, and apackage 120 that stores the physical quantity sensor 1 and the circuitelement 110. The physical quantity sensor 1 is not limited inparticular, for example, the configuration of the above-describedembodiment can be used as the physical quantity sensor. The physicalquantity sensor device 100 can be suitably used as an inertialmeasurement unit (IMU).

The circuit element 110 (IC) is bonded to the lid 10 of the physicalquantity sensor 1 via a bonding member. In addition, the circuit element110 is electrically connected to each terminal T of the physicalquantity sensor 1 via a bonding wire BW1 and is electrically connectedto the package 120 (an internal terminal 133 to be described below) viaa bonding wire BW2. The circuit element 110 includes a drive circuitthat drives the physical quantity sensor 1, a detection circuit thatdetects acceleration based on an output signal from the physicalquantity sensor 1, a correction circuit that corrects the detectedacceleration, an output circuit that converts a signal from thedetection circuit into a predetermined signal and outputs the signal,and the like, as necessary. The circuit element 110 may be providedoutside the package 120 or may be omitted.

The package 120 includes a base 130 and a lid 140 bonded to an uppersurface of the base 130 so as to form a storage space S1 for storing thephysical quantity sensor 1 and the circuit element 110 between the base130 and the lid.

The base 130 has a cavity shape including a recessed portion 131 whoseupper surface is open. In addition, the recessed portion 131 includes afirst recessed portion 131 a which is open on an upper surface of thebase 130 and a second recessed portion 131 b which is open on a bottomsurface of the first recessed portion 131 a.

Meanwhile, the lid 140 has a plate shape and is bonded to an uppersurface of the base 130 so as to close an opening of the recessedportion 131. In this way, the storage space S1 is formed by closing theopening of the recessed portion 131 with the lid 140, and the physicalquantity sensor 1 and the circuit element 110 are stored in the storagespace S1.

The storage space S1 is airtightly sealed and has the same atmosphere asthe storage space S of the physical quantity sensor 1. Thereby, even ifairtightness of the storage space S is collapsed and the storage space Scommunicates with the storage space S1, the atmosphere in the storagespace S can be maintained as it is. Accordingly, it is possible tosuppress a change in physical quantity detection characteristics of thephysical quantity sensor 1 due to a change in the atmosphere of thestorage space S, and the physical quantity sensor device 100 can performa stable drive. The “same atmosphere” is not limited to a case ofperfect matching, and also includes a case where there is an inevitablemanufacturing error such as slightly different pressures in both spaces.In addition, the atmosphere of the storage space S1 does not have to bethe same as the storage space S.

A configuration material of the base 130 is not limited in particular,and various ceramics, for example, oxide ceramics such as alumina,silica, titania, and zirconia, nitride ceramics such as silicon nitride,aluminum nitride, and titanium nitride, or the like can be used as theconfiguration material. In this case, the base 130 can be manufacturedby baking a staking body of a ceramic sheet (green sheet). With such aconfiguration, it is possible to simply form the recessed portion 131.

In addition, a material of the lid 140 is not limited in particular, andmay be a member having a linear expansion coefficient close to a linearexpansion coefficient of the configuration material of the base 130. Forexample, in a case where the configuration material of the base 130 isceramics described above, it is preferable to use an alloy such asKovar.

In addition, the base 130 includes a plurality of internal terminals 133arranged on a bottom surface of the first recessed portion 131 a and aplurality of external terminals 134 arranged on a lower surface. Eachinternal terminal 133 is electrically connected to a predeterminedexternal terminal 134 via an internal wire (not illustrated) disposed inthe base 130. In addition, each of the plurality of internal terminals133 is electrically connected to the circuit element 110 via the bondingwire BW2. Thereby, the outside of the package 120 can be electricallyconnected to the circuit element 110, and the physical quantity sensordevice 100 can be easily mounted.

The physical quantity sensor device 100 is described above. As describedabove, the physical quantity sensor device 100 includes the physicalquantity sensor 1 and the circuit element 110. Accordingly, the effectsof the aforementioned physical quantity sensor 1 can be obtained, andthe physical quantity sensor device 100 has a high reliability.

The configuration of the physical quantity sensor device 100 is notlimited in particular, and, for example, the physical quantity sensor 1and the circuit element 110 may be disposed in reverse. That is, thecircuit element 110 may be disposed on the bottom surface of therecessed portion 131, and the physical quantity sensor 1 may be disposedon the upper surface of the circuit element 110. In addition, thecircuit element 110 and the physical quantity sensor 1 may be moldedwith a molding material without the package 120.

Sixth Embodiment

An electronic apparatus according to a sixth embodiment will bedescribed.

FIG. 13 is a perspective view illustrating the electronic apparatusaccording to the sixth embodiment.

A mobile type (or notebook type) personal computer 1100 illustrated inFIG. 13 is an apparatus to which the electronic apparatus according tothe invention is applied. In this figure, the personal computer 1100 isconfigured with a main body portion 1104 including a keyboard 1102, anda display unit 1106 including a display portion 1108. The display unit1106 is rotatably supported to the main body portion 1104 via a hingestructure portion.

The personal computer 1100 stores the physical quantity sensor 1, acontrol circuit 1110 that controls driving of the physical quantitysensor 1, and a correction circuit 1120 that corrects a physicalquantity detected by the physical quantity sensor 1, for example, basedon the ambient temperature therein. The physical quantity sensor 1 isnot limited in particular, and can also be used for, for example, any ofthe respective embodiments described above.

The personal computer 1100 (electronic apparatus) includes the physicalquantity sensor 1, the control circuit 1110, and the correction circuit1120. Accordingly, the effects of the physical quantity sensor 1described above can be obtained, and a high reliability can be exerted.

Seventh Embodiment

An electronic apparatus according to a seventh embodiment will bedescribed.

FIG. 14 is a perspective view illustrating the electronic apparatusaccording to the seventh embodiment.

A portable phone 1200 (including PHS) illustrated in FIG. 14 is anapparatus to which the electronic apparatus according to the inventionis applied. In this figure, the portable phone 1200 includes an antenna(not illustrated), a plurality of operation buttons 1202, an earpiece1204, and a mouthpiece 1206. A display unit 1208 is disposed between theoperation button 1202 and the earpiece 1204.

The portable phone 1200 stores the physical quantity sensor 1, a controlcircuit 1210 that controls driving of the physical quantity sensor 1,and a correction circuit 1220 that corrects a physical quantity detectedby the physical quantity sensor 1, for example, based on the ambienttemperature therein. The physical quantity sensor 1 is not limited inparticular, and may be used for, for example, any of the above-describedembodiments.

The portable phone 1200 (electronic apparatus) described above includesthe physical quantity sensor 1, the control circuit 1210, and thecorrection circuit 1220. Accordingly, the effects of the physicalquantity sensor 1 described above can be obtained, and a highreliability can be exerted.

Eighth Embodiment

An electronic apparatus according to an eighth embodiment will bedescribed.

FIG. 15 is a perspective view illustrating the electronic apparatusaccording to the eighth embodiment.

A digital still camera 1300 illustrated in FIG. 15 is an apparatus towhich the electronic apparatus according to the invention is applied. Inthis figure, a display unit 1310 is provided on a rear surface of a case1302, the display unit is configured to perform display based on animage-capturing signal from a CCD, and the display unit 1310 functionsas a viewfinder for displaying a subject as an electronic image. Inaddition, a light receiving unit 1304 including an optical lens(image-capturing optical system), the CCD or the like is provided on afront side (a back side in the figure) of the case 1302. If an imagecapturing person confirms a subject image displayed on the display unit1310 and presses a shutter button 1306, an image-capturing signal of theCCD is transferred and stored in the memory 1308 at that time.

The digital still camera 1300 stores the physical quantity sensor 1, acontrol circuit 1320 that controls driving of the physical quantitysensor 1, a correction circuit 1330 that corrects a physical quantitydetected by the physical quantity sensor 1, for example, based on theambient temperature therein. The physical quantity sensor 1 is notparticularly limited, but any of the above-described embodiments can beused, for example.

The digital still camera 1300 (electronic apparatus) includes thephysical quantity sensor 1, the control circuit 1320, and the correctioncircuit 1330. Accordingly, the effects of the physical quantity sensor 1described above can be obtained, and a high reliability can be exerted.

In addition to the personal computer and the portable phone according tothe embodiments described above, and the digital still camera accordingto the present embodiment, the electronic apparatus according to theinvention can be applied to, for example, a smartphone, a tabletterminal, a watch (including a smart watch), an ink jet type ejectiondevice (for example, an ink jet printer), a laptop type personalcomputer, a television, a wearable terminal such as a head mounteddisplay (HMD), a video camera, a video tape recorder, a car navigationdevice, a pager, an electronic notebook (including a communicationfunction), an electronic dictionary, a calculator, an electronic gamemachine, a word processor, a workstation, a videophone, a televisionmonitor for crime prevention, an electronic binocular, a POS terminal, amedical apparatus (for example, an electronic clinical thermometer, asphygmomanometer, a blood glucose meter, an electrocardiogrammeasurement device, an ultrasonic diagnostic device, an electronicendoscope), a fish finder, various measuring instruments, an apparatusfor mobile terminal base station, instruments (for example, instrumentsof a vehicle, an aircraft, and a ship), a flight simulator, a networkserver, and the like.

Ninth Embodiment

A portable electronic apparatus according to a ninth embodiment will bedescribed.

FIG. 16 is a plan view illustrating the portable electronic apparatusaccording to the ninth embodiment. FIG. 17 is a functional block diagramillustrating a schematic configuration of the portable electronicapparatus illustrated in FIG. 16.

A watch type activity meter 1400 (active tracker) illustrated in FIG. 16is a wrist apparatus to which the portable electronic apparatusaccording to the invention is applied. The activity meter 1400 isattached to a part (subject) such as the wrist of a user by a band 1401.In addition, the activity meter 1400 includes a display unit 1402 fordigital display and can perform wireless communication. The physicalquantity sensor 1 according to the invention described above isincorporated in the activity meter 1400 as a sensor that measuresacceleration or a sensor that measures an angular velocity.

The activity meter 1400 includes a case 1403 storing the physicalquantity sensor 1, a processing unit 1410 that is stored in the case1403 and processes output data from the physical quantity sensor 1, adisplay unit 1402 stored in the case 1403, and a light-transmittingcover 1404 that closes an opening of the case 1403. In addition, a bezel1405 is provided outside the light-transmitting cover 1404. In addition,a plurality of operation buttons 1406 and 1407 are provided on a sidesurface of the case 1403.

As illustrated in FIG. 17, an acceleration sensor 1408 serving as thephysical quantity sensor 1 detects accelerations in three axialdirections intersecting (ideally orthogonal to) each other, and outputsa signal (acceleration signal) according to magnitudes and orientationsof the detected three axial accelerations. In addition, an angularvelocity sensor 1409 detects each angular velocity in three axialdirections intersecting (ideally orthogonal to) each other, and outputsa signal (angular velocity signal) according to magnitudes andorientations of the detected three axial angular velocities.

A liquid crystal display (LCD) configuring the display unit 1402displays, for example, location information obtained by using a GPSsensor 1411 or a geomagnetic sensor 1412, exercise information such asthe amount of movement or the amount of exercise obtained by using theacceleration sensor 1408 or the angular velocity sensor 1409 included inthe physical quantity sensor 1, biometric information such as a pulserate obtained by using a pulse sensor 1413 or the like, time informationsuch as current time, or the like in accordance with various detectionmodes. It is also possible to display an environmental temperatureobtained by using a temperature sensor 1414.

A communication unit 1415 performs various controls for establishingcommunication between a user terminal and an information terminal (notillustrated). The communication unit 1415 is configured to include, forexample, a transmission and reception apparatus corresponding to a shortrange wireless communication standard such as Bluetooth (registeredtrademark) (including Bluetooth low energy (BTLE)), Wireless-Fidelity(Wi-Fi: registered trademark), Zigbee (registered trademark), near fieldcommunication (NFC), and ANT+ (registered trademark), and a connectorcorresponding to a communication bus standard such as the UniversalSerial Bus (USB), and the like.

The processing unit 1410 (processor) is configured with, for example, amicro processing unit (MPU), a digital signal processor (DSP), anapplication specific integrated circuit (ASIC) or the like. Theprocessing unit 1410 performs various types of processing, based on aprogram stored in the storage unit 1416 and a signal input from theoperation unit 1417 (for example, the operation buttons 1406 and 1407).Processing performed by the processing unit 1410 includes dataprocessing for each output signal of the GPS sensor 1411, thegeomagnetic sensor 1412, a pressure sensor 1418, the acceleration sensor1408, the angular velocity sensor 1409, the pulse sensor 1413, thetemperature sensor 1414, and a clocking unit 1419, display processingfor displaying an image on the display unit 1402, sound outputprocessing for outputting a sound to a sound output unit 1420,communication processing for communicating with an information terminalvia the communication unit 1415, power control processing for supplyingpower from the battery 1421 to each unit, and the like.

The activity meter 1400 can have at least the following functions.

1. Distance: a total distance from start of measurement performed by ahighly accurate GPS function is measured.

2. Pace: a current driving pace is displayed from pace distancemeasurement.

3. Average speed: average speed from an average speed travel start to acurrent point of time is calculated and displayed.

4. Altitude: altitude is measured and displayed by the GPS function.

5. Stride: a stride is measured and displayed even in a tunnel where aGPS radio wave does not reach.

6. Pitch: the number of steps per minute is measured and displayed.

7. Heart rate: a heart rate is measured and displayed by a pulse sensor.

8. Gradient: a gradient of the ground is measured and displayed intraining and trail runs in the mountain.

9. Auto wrap: when a person runs for a fixed distance set in advance orfor a fixed time, a lap measurement is automatically performed.

10. Exercise consumption calorie: burned calories are displayed.

11. Step count: the total number of steps from exercise start isdisplayed.

The activity meter 1400 (portable electronic apparatus) includes thephysical quantity sensor 1, the case 1403 storing the physical quantitysensor 1, the processing unit 1410 that is stored in the case 1403 andprocesses output data from the physical quantity sensor 1, the displayunit 1402 stored in the case 1403, and the light-transmitting cover 1404closing an opening portion of the case 1403. Accordingly, the effects ofthe physical quantity sensor 1 described above can be obtained and ahigh reliability can be exerted.

The activity meter 1400 can be widely applied to a running watch, arunner's watch, a runner's watch corresponding to multi-sports such asduathlon and triathlon, an outdoor watch, a GPS satellite positioningsystem such as a GPS watch in which GPS is mounted, and the like.

In addition, in the above description, a global positioning system (GPS)is used as a satellite positioning system, but another global navigationsatellite system (GNSS) may be used. For example, one or more of thesatellite positioning systems such as a European geostationary satellitenavigation overlay service (EGNOS), a Quasi Zenith satellite system(QZSS), a global navigation satellite system (GLONASS), GALILEO, and aBei Dou navigation satellite system (Bei Dou) may be used. In addition,a stationary satellite type satellite-based augmentation system (SBAS)such as a wide area augmentation system (WAAS), and a Europeangeostationary-satellite navigation overlay service (EGNOS) may be usedto at least one of the satellite positioning system.

Tenth Embodiment

A vehicle according to a tenth embodiment will be described.

FIG. 18 is a perspective view illustrating the vehicle according to thetenth embodiment.

An automobile 1500 illustrated in FIG. 18 is an automobile to which thevehicle according to the invention is applied. In this figure, theautomobile 1500 stores the physical quantity sensor 1 functioning as atleast one (preferably a composite sensor capable of detecting both) ofan acceleration sensor and an angular velocity sensor therein, and aposture of a vehicle body 1501 can be detected by the physical quantitysensor 1. A detection signal of the physical quantity sensor 1 issupplied to a vehicle body posture control device 1502 (posture controlunit), and the vehicle body posture control device 1502 detects theposture of the vehicle body 1501, based on the signal, and hardness of asuspension can be controlled or brakes of individual wheels 1503 can becontrolled according to the detection results. Here, for example, thesame element as in the above-described embodiments can be used as thephysical quantity sensor 1.

The automobile 1500 (vehicle) includes the physical quantity sensor 1and a vehicle body posture control device 1502 (posture control unit).Accordingly, the effects of the physical quantity sensor 1 describedabove can be obtained, and a high reliability can be exerted.

In addition to this, the physical quantity sensor 1 can be widelyapplied to a car navigation system, a car air conditioner, an anti-lockbraking system (ABS), an air bag, a tire pressure monitoring system(TPMS), an engine control, and an electronic control unit (ECU) such asa battery monitor of a hybrid vehicle or an electric vehicle.

In addition, the vehicle is not limited to the automobile 1500, and canalso be applied to, for example, an airplane, a rocket, an artificialsatellite, a ship, an automated guided vehicle (AGV), a biped walkingrobot, an unmanned airplane such as a drone, and the like.

As described above, although a physical quantity sensor, a physicalquantity sensor device, an electronic apparatus, a portable electronicapparatus, and a vehicle according to the invention are described basedon the illustrated embodiments, the invention is not limited to this,and configurations of each portion can be replaced with anyconfiguration having the same function. In addition, any otherconfiguration unit may be added to the invention. In addition, theabove-described embodiments may be appropriately combined. For example,the elements 3, 4, 5, and 6 may have configurations different from eachother, and a configuration according to another embodiment differentfrom the first, second, third, and fourth embodiments described abovemay be adopted.

In addition, in the above-described embodiment, a case whereacceleration is detected by a physical quantity sensor is described, butthe invention is not limited to this, and, for example, an angularvelocity may be detected. In addition, both the acceleration and theangular velocity may be detected.

The entire disclosure of Japanese Patent Application No. 2017-182170,filed Sep. 22, 2017 is expressly incorporated by reference herein.

What is claimed is:
 1. A physical quantity sensor comprising: three axesorthogonal to each other being defined as an X axis, a Y axis, and a Zaxis; a substrate that is rectangular-shaped, the substrate havingfirst, second, third, and fourth sides, the first and second sidesextending along the Y axis and being opposite to each other, the thirdand fourth sides extending along the X axis and being opposite to eachother; a recess formed in a center area of the substrate along the Zaxis to provide first, second, third, and fourth ledges of the substratealong the first, second, third, and fourth aides of the substrate; afirst sensor element configured to detect an acceleration along the Xaxis, the first sensor element being configured with: a pair of firstfixing electrodes, each of the pair of first fixing electrodes having afirst trunk and a first fixing electrode finger, the first trunkextending along the X axis, the first fixing electrode finger extendingalong the Y axis and branching out from the first trunk, an end of thefirst trunk being fixed only on the first ledge of the substrate; afirst fixing portion extending along the X axis and parallel to thefirst trunks of the air of first fixing electrodes, an end of the firstfixing portion being fixed only on the first ledge of the substrate,lengths of the first trunks of the pair of first fixing electrodes andthe first fixing portion being substantially the same; a first movableportion extending along the second, third, and fourth sides of thesubstrate to surround the pair of first fixing electrodes and the firstfixing portion, a first movable electrode finger extending along the Yaxis and branching out from the first movable portion, the first movableelectrode finger facing the first fixing electrode fingers along the Xaxis; and a first spring connecting the other end of the first fixingportion to the first movable portion; a second sensor element configuredto detect the acceleration along the X axis, the second sensor elementbeing configured with: a pair of second fixing electrodes, each of thepair of second fixing electrodes having a second trunk and a secondfixing electrode finger, the second trunk extending along the X axis,the second fixing electrode finger extending along the Y axis andbranching out from the second trunk, an end of the second trunk beingfixed only on the second ledge of the substrate; a second fixing portionextending along the X axis and parallel to the second trunks of the pairof second fixing electrodes, an end of the second fixing portion beingfixed only on the second ledge of the substrate, lengths of the secondtrunks of the pair of second fixing electrodes and the second fixingportion being substantially the same; a second movable portion extendingalong the first, third, and fourth sides of the substrate to surroundthe pair of second fixing electrodes and the second fixing portion, asecond movable electrode finger extending along the Y axis and branchingout from the second movable portion, the second movable electrode fingerfacing the second fixing electrode fingers along the X axis; and asecond spring connecting the other end of the second fixing portion tothe second movable portion; a third sensor element configured to detectan acceleration along the Y axis, the third sensor element beingconfigured with: a pair of third fixing portion electrodes, each of thepair of third fixing electrodes having a third trunk and a third fixingelectrode finger, the third trunk extending along the Y axis, the thirdfixing electrode finger extending along the X axis and branching outfrom the third trunk, an end of the third trunk being fixed only on thethird ledge of the substrate; a third fixing portion extending along theY axis and parallel to the third trunks of the pair of third fixingelectrodes, an end of the third fixing portion being fixed only on thethird ledge of the substrate, lengths of the third trunks of the pair ofthird fixing electrodes and the third fixing portion being substantiallythe same; a third movable portion extending along the first, second, andfourth sides of the substrate to surround the pair of third fixingelectrodes and the third fixing portion, a third movable electrodefinger extending along the X axis and branching out from the thirdmovable portion, the third movable electrode finger facing the thirdfixing electrode fingers along the Y axis; and a third spring connectingthe other end of the third fixing portion to the third movable portion;and a fourth sensor element configured to detect the acceleration alongthe Y axis, the fourth sensor element being configured with: a pair offourth fixing electrodes, each of the pair of fourth fixing electrodeshaving a fourth fixing electrode finger, the fourth trunk extendingalong the Y axis, the fourth fixing electrode finger extending along theX axis and branching out from the fourth trunk, an end of the fourthtrunk being fixed only on the fourth ledge of the substrate; a fourthfixing portion extending along the Y axis and parallel to the fourthtrunks of the pair of fourth fixing electrodes, an end of the fourthfixing portion being fixed only on the fourth ledge of the substrate,lengths of the fourth trunks of the pair of fourth fixing electrodes andthe fourth fixing portion being substantially the same; a fourth movableportion extending along the first, second, and third sides of thesubstrate to surround the pair of fourth fixing electrodes and thefourth fixing portion, a fourth movable electrode finger extending alongthe X axis and branching out from the fourth movable portion, the fourthmovable electrode finger facing the fourth fixing electrode fingersalong the Y axis; and a fourth spring connecting the other end of thefourth fixing portion to the fourth movable portion.
 2. The physicalquantity sensor according to claim 1, wherein the first, second, third,and fourth movable portions are cantilever-supported to the first,second, third, and fourth fixing portions via the first, second, third,and fourth springs, respectively.
 3. A physical quantity sensor devicecomprising: the physical quantity sensor according to claim 2; and acircuit element.
 4. An electronic apparatus comprising: the physicalquantity sensor according to claim 2; a control circuit; and acorrection circuit.
 5. A portable electronic apparatus comprising: thephysical quantity sensor according to claim 2; a case that stores thephysical quantity sensor; a processing unit that is stored in the caseand processes output data from the physical quantity sensor; a displayunit that is stored in the case; and a light-transmitting cover thatcovers an opening of the case.
 6. A vehicle comprising: the physicalquantity sensor according to claim 2; and a posture control unit.
 7. Aphysical quantity sensor device comprising: the physical quantity sensoraccording to claim 1; and a circuit element.
 8. An electronic apparatuscomprising: the physical quantity sensor according to claim 1; a controlcircuit; and a correction circuit.
 9. A portable electronic apparatuscomprising: the physical quantity sensor according to claim 1; a casethat stores the physical quantity sensor; a processing unit that isstored in the case and processes output data from the physical quantitysensor; a display unit that is stored in the case; andalight-transmitting cover that covers an opening of the case.
 10. Avehicle comprising: the physical quantity sensor according to claim 1;and posture control unit.